Means for casting

ABSTRACT

In continuous casting, such as dipforming wire, a furnace is used, which is divided into at least three spaces. A first part comprises an inlet part to be filled with melt from a melting furnace, a second part communicates with the lower portion of the first part and is provided with at least one gas inlet and is connected to at least one inductive heating unit of the channeltype induction furnace type, and a third part has an outlet nozzle or casting opening for feeding melt into a casting equipment, which third part communicates with the lower portion of the second part.

United States Patent Fredrikson et al. 1451 Aug. 22, 1972 541 MEANS FOR CASTING [56] References Cited [72] Inventors: Bengt Fredrikson, Kallgafrn 98; UNITED STATES PATENTS Larsen 54; 2,648,716 8/1953 Lindner et al. 164/251 x Erkkl 5mm", Mlolnars vag 5, 2,936,326 5/1960 Tama ..164/251 x of Vasteras, Sweden 3,095,464 6/1963 Tagliaferri ..13/29 [22] Filed: June 17, 1971 3,484,280 12/1969 Carreker ..164/281 X PP N04 154,046 Primary Examiner-Robert D. Baldwin Related US. Application Data Attorney jennmgs Halley Jr' [63] Continuation-in-part of Ser. No. 875,162, Nov. ABSTRACT 1969, abandonedln continuous casting, such as dipforming wire, a furnace is used, which is divided into at least three [30] Foreign Application Priority Data spaces. A first part comprises an inlet part to be filled with melt from a melting furnace, a second part com- Nov. 14, 1968 Sweden ..l543l/68 municates with the lower portion of the first part and is provided with at least one gas inlet and is connected [52] US. Cl. ..164/251, l3/29, l64/28l to at least one inductive heating unit of the Channel Int. Cl 11/10, 322d 27/02 type induction furnace type, and a part has an [58] Field of Search 1 64/25 1 51, 281, 266; 13/29 outlet nozzle or casting opening for feeding melt into a casting equipment, which third part communicates with the lower portion of the second part.

3 Claims, 3 Drawing Figures Iii Patented Aug. 22, 1972 3,685,570

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NGT F zeoeems 0N STE: IN LARSEN ERKKI so Patented Aug. 22, 1972 2 Sheets-Sheet 2 Fig 3 1 MEANS FOR CASTING PRIOR APPLICATIONS This application is a continuation-in-part of application Ser. No. 875,162, filed Nov. 10, 1969, now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a means for casting, such as dipforming wire, continuous casting or the like.

2. The Prior Art Such dip-forming of wire has previously been carried out with the help of a resistance heating unit from which melt is led to a container having a pressure medium tank communicating with a gas supply means with variable pressure, the pressure in the clock determining the level of the melt in and around the tank. The space around the tank is in turn in communication with the outlet nozzle to a casting crucible through which a wire is drawn. The melt, which consists of copper, aluminum or similar material or alloys of one of these materials, is frozen on to the wire (coated), which is usually of the same material, and a thicker wire is obtained which is in turn rolled or drawn to the desired dimension, after which it may be used to a certain extent as core wire for continued casting.

One disadvantage with such equipment, particularly the space containing the pressure medium tank, is that the space is not fully utilized, partly because of the bulky pressure medium tank. There is some difficulty in obtaining an effectively homogenized melt and the level control is hardly free of disturbance, with risk of oscillations of the surface. There is also the risk of accidents in the tank and the container and the equipment is relatively expensive. Similar difficulties exist when using the equipment for continuous casting and the like.

SUMMARY OF THE INVENTION These and other disadvantages are eliminated according to the invention, which is characterized in that it consists of a furnace or container divided into at least three spaces, the first part comprising an inlet part to be filled with melt from a melting furnace, a second part, the furnace hearth, communicating with the lower part of the first-mentioned part, provided with at least one gas inlet and connected to at least one inductive heating unit of the channel-type induction furnace type, and a third part, the outlet part, with a nozzle or casting opening for feeding melt into casting equipment, the third part communicating with the hearth part.

Such an arrangement provides considerably more effective utilization of the furnace (container) spaces, and, because of the presence of heating or heat-retaining members in the hearth part, the melt is prevented from freezing in the furnace spaces. The well-known pinch effect in the channels of the inductor unit also has a certain pressure effect on the melt in the hearth part, which also provides a certain stirring and temperature-equalization effect, without having to use separate stirrers.

In the preferred embodiments the inlet part communicates with the hearth part and the hearth part with the outlet part at the. lower parts of the spaces and the levels of the melt can be adjusted by varying the gas pressure on the surface of the hearth part and thus, because of the law for communicating vessels, in the outlet part as well, and the surface can be kept above or below the upper edge of the outlet nozzle to the casting crucible and varied as required by altered outlet level and other conditions. The level can be adjusted without much risk of variations in level, the formation of waves or the like which might otherwise cause disturbance.

BRIEF DESCRIPTION OF THE DRAWINGS The device is exemplified in the accompanying drawings in which FIGS. 1 and 2 show in vertical and horizontal cross-section respectively (FIG. 1 on the line A-A of FIG. 2) the casting equipment and FIG. 3 shows in principle so-called dip-forming of wire.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 3 shows how melt is fed by hydrostatic pressure through a nozzle 11 around a passing wire 12 in a casting chamber. The melt and the wire should be of the same material. The wire emerging from the casting crucible has naturally greater dimensions than that entering the crucible and can be drawn or rolled to the desired dimensions, and possibly used again as corewire for further wire production. It must of course be possible to vary the level in the casting crucible and there should not be any noticeable amount of slag or other impurities in the melt fed in (Cu, Al or some other metal or alloy).

The fumace or container from which the melt is fed into the casting crucible is shown in FIGS. 1 and 2. Melt is filled into the siphon-shaped inlet 13 (FIG. 2) and this shape enables slag and lining particles to be easily removed from the surface of the melt in this inlet by means of slag-removing members (not shown). The inlet 13 communicates, preferably at its lower part, through a passage 21 with the lower part of a central part, the hearth 14, to which at least one inductor unit 15 of the channel-type induction furnace type (submerged-resistor type) is connected, suitably replaceable in accordance with Swedish patent No. 185,973. At least one conduit 16 for gas (combustion gas, cracked ammonia, nitrogen, inert gas or the like) opens out over the melt surface in the space 14 and, by means of a gas supply member, not shown in the drawings, the desired pressure and thus the desired level of the melt can be adjusted in the space 14. The lower part of the hearth l4 communicates through a passage 22 with the lower part of an outlet part 17 having a nozzle or casting opening 18. Thus, by suitable selection of the pressure above the surface in the hearth 14, the correct level can be chosen in the outlet part 17, suitably above or below the upper edge of the nozzle 18.

The inductor 15 is provided with melt channels 23 opening entirely into the second space 14, but close to the connecting passages 21 and 22 leading to the first space 13 and third space 17, respectively. The melt channels run perpendicular to the connecting passages. Thus the pinch-eflect will cause some stirring and the homogenization in space 14 and the heating effect will prevent freezing of the melt also in the connecting passages. The changes in pressure, caused by the pincheffect, will appear in the second chamber 14, but oscillations in the melt surface in this space will be equalized or damped out in the connecting channel 22 to the third chamber 17 and in the third chamber 17 and they will not cause any uneven spraying at the nozzle 18 or the like.

Because of the flow through the three spaces and because of the pinch-eflect in the channels of the inductor unit (s) a homogenization of the melt is obtained in the whole furnace and also satisfactory temperature equalization. Even with considerable alterations in level due to altered gas pressure, level oscillations or waves are avoided and thus disturbances also.

The equipment can thus be made relatively free of disturbances. There is no risk of the melt becoming cold since the heating unit (inductor unit(s) can be given sufficient power to prevent this, even in the outlet part 17. The latter may be provided with a removable lid 19 for inspection and cleaning.

The chambers 13 and 17 are both located on the same side of the hearth 14, and the connecting passages 21 and 22 thus extend from the same side of the hearth. The melt channels 23 open into the bottom of the hearth offset from the center of the hearth and adjacent the openings thereinto of the connecting passages.

Protective gas may be supplied to the outlet part 17 and, through a special smaller channel 20, to the inlet part. This may also be introduced in the rest of the system in order to prevent oxidization of the melt, and

the whole equipment should be made gas-tight.

In the case shown the means is used for dip-forming wire, but it may also be used with the same good results for continuous casting or other similar processes, and

the means according to the invention may be given other embodiments within the scope of the following claims.

We claim:

1. Means for continuous casting, such as dip-forming wire, comprising a furnace divided into three spaces, the first space comprising an inlet part adapted to be filled with melt from a melting furnace, the second space being provided with a least one gas inlet and having at least one inductor unit of submerged resistor type connected therewith and with the ends of its melt channels ending in said second space, means separating the first and second spaces except for one connecting passage at the lower portion of said first and second spaces, means separating the second and third spaces except for one connecting passage at the lower portion of the second and third spaces, and a nozzle communicating with the third space at a substantial distance below the top thereof, opening into a continuous casting device, the melt channels of the inductors opening into the second space adjacent the openings of the connecting channels into such second space to provide stirring and homogenization in said second space and to prevent freezing of the melt in said connecting channels.

2. Means as claimed in claim 1, in which the first and third chambers are on the same side of the second chamber.

3. Means as claimed in claim 2, in which the connecting passages open into the same side of the second chamber and the melt channels open into the second chamber at points offset from the center thereof towards said side. 

1. Means for continuous casting, such as dip-forming wire, comprising a furnace divided into three spaces, the first space comprising an inlet part adapted to be filled with melt from a melting furnace, the second space being provided with at least one gas inlet and having at least one inductor unit of submerged resistor type connected therewith and with the ends of its melt channels ending in said second space, means separating the first and second spaces except for one connecting passage at the lower portion of said first and second spaces, means separating the second and third spaces except for one connecting passage at the lower portion of the second and third spaces, and a nozzle communicating with the third space at a substantial distance below the top thereof opening into a continuous casting device, the melt channels of the inductors opening into the second space adjacent the openings of the connecting channels into such second space to provide stirring and homogenization in said second space and to prevent freezing of the melt in said connecting channels.
 2. Means as claimed in claim 1, in which the first and third chambers are on the same side of the second chamber.
 3. Means as claimed in claim 2, in which the connecting passages open into the same side of the second chamber and the melt channels open into the second chamber at points offset from the center thereof towards said side. 